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Funding Acknowledgements Type of funding sources: None. Background Acute coronary syndrome (ACS) patients are associated with a higher risk of adverse cardiac events after percutaneous coronary intervention (PCI). A lower threshold level of low density cholesterol (LDL), less than 50 mg/dL, as recommended by most recent guidelines, has been associated with a lower risk of such events. An early and more pronounced achievement of such target LDL level could confer benefit to this high risk patient category. It is not known whether prior treatment with statins might have such beneficial effect in patients admitted with acute coronary syndromes undergoing PCI. Purpose To study the role of prior statin use in patients admitted with ACS and treated with PCI regarding the achievement of target LDL threshold. Methods We prospectively enrolled 400 consecutive ACS patients who underwent PCI treatment in our hospital. We collected peri- and postprocedural clinical and laboratory data; all patients were followed up and were asked to have their lipid profile measured at 1 month after discharge. Patients were divided in 2 groups: patients who were already on statin treatment on admission (group 1) and those who were not (group 2). Primary endpoint was achievement of target LDL threshold in accordance with current ESC guidelines 1 month after discharge, and secondary endpoint was in-hospital and 30-day occurrence of major adverse events (death, nonfatal myocardial infarction and re-hospitalization). Results Out of 400 patients, 105 of them composed group 1 and 295 patients composed group 2. Mean age was 64.96 +/- 10.26 years. 74.8% were males. 94.8% suffered from arterial hypertension, 41% from diabetes and 56.3% were active smokers. On admission, mean LDL level was 118.15 +/- 42.67 mg/dL in group 1 and 141.66 +/- 44.14 mg/dL in group (p= Conclusion In patients with acute coronary syndrome who are treated with PCI, prior treatment with statin, despite a numerically more favorable outcome, has no statistically significant impact on achievement of LDL target threshold in accordance with current guidelines or in in-hospital and 30-day MACE occurrence.

Funding Acknowledgements Type of funding sources: None. Background The recent Avoiding Transvenous Leads in Appropriate Subjects (ATLAS) Trial demonstrated that the subcutaneous implantable cardioverter–defibrillator (S-ICD) reduces lead-related complications without significantly compromising the effectiveness of ICD shocks, but with more early postoperative pain. Purpose To assess the perioperative and postoperative pain during S-ICD implantation in current clinical practice and evaluate the influence of implantation techniques. Methods We analyzed 255 consecutive patients (84% male, 52±16 years, body mass index 26±4 Kg/m², ejection fraction 42±16%) who had undergone S-ICD implantation from 2017 to 2022. The primary endpoint was pain during S-ICD placement. The secondary outcome measure included static and dynamic pain intensity 6 hours after the end of the procedure. Patients were asked to rate pain intensity on a 10-point visual analogue scale from 0 (no pain) to 10 (worst imaginable pain). Results The mean procedure duration was 62±22 minutes. The serratus anterior plane block (SAPB) was performed in 161 (63%) patients for anesthesia/analgesia, and 161 (63%) patients underwent the defibrillation testing. Implantation success was reported in all patients with no operative complications. In the overall group, the pain intensity was 2 [range: 1-8] during the implantation procedure, and 1 [1-7] for both static and dynamic pain, 6 hours after the end of the procedure. Significantly lower values were recorded during implantation in the SAPB group (p=0.010) and among those who did not undergo the defibrillation testing (p=0.008). The adoption of the SAPB (coefficient: -0.54, p=0.047) and the omission of defibrillation testing (coefficient: -0.70, p=0.028) remained associated with less pain during implantation after correction for age, sex, body habitus, ejection fraction. Six hours after the end of the procedure the static and dynamic pain intensity remained lower among those with omitted testing (p=0.018 and 0.004, respectively). Conclusions In current clinical practice, S-ICD implantation is associated with very little discomfort. The adoption of novel anesthetic techniques and the omission of defibrillation testing is associated with lower pain levels.

Introduction Ventricular arrhythmias (VA) represent a common complication of myocardial infarction (MI). Typically, they occur in two scenarios: during acute MI, related to ongoing ischemia, as ventricular tachycardia (VT) or ventricular fibrillation (VF), or in the context of a late phase of MI, related to the presence of a scar, as monomorphic VT (mVT). Despite the above, their occurrence may be atypical. Clinical Case 55–year–old man affected by obesity, diabetes and hypertension, admitted to our department for subacute MI. Coronarography showed three–vessel disease with indication for surgical revascularization. Thirty hours after admission, in absence of symptoms, occurrence of cardiovascular arrest due to mVT, which degenerated into VF. After resuscitation, ECG and Echo findings did not change compared to those observed at admission, excluding the presence of current ischemia. A blood gas analysis excluded dysionias. Few minutes later, arrhythmic recurrence of mVT degenerated into VF. This was refractory to electrical and antiarrhythmic therapy and stopped only after percutaneous left stellate ganglion block (LSGB) and deep sedation. Then, emergency surgical revascularization was performed. In the early postoperative days, during weaning attempts from sedation and ECMO support, that had become necessary due to hemodynamic instability after surgery, numerous recurrences of mVT, regressed only after deepening of sedation, multiple external shocks, antiarrhythmic polytherapy, and LSGB. A new coronarography documented patency of coronary artery bypass grafts. On 6th postoperative day, discontinuation of deep sedation and weaning from circulatory support without recurrence of VA. The patient was discharged from the intensive care unit and started on a rehabilitation pathway. Conclusions mVTs are commonly related to the presence of a scar, formed late after MI, or to the context of ongoing ischemia in acute MI. However, it should be remembered that even during the subacute phase of MI, arrhythmic instability might still occur. The responsible mechanisms are not completely known but it can be assumed that, even in the absence of a new ischemic event, the process of scar maturation may have led to a transient proarrhythmic substrate, responsible for the arrhythmic storm. Further studies are needed to clarify the mechanisms of arrhythmogenesis in the subacute phase of MI.

Introduction The prevention of sudden cardiac death (SCD) through the implantation of a defibrillator (ICD) represents one of the fundamental milestones in the management of arrhythmogenic cardiomyopathy (ACM). Individual characteristics of the patient and of the disease can help in the selection of the device [transvenous (TV) or subcutaneous (S–ICD) defibrillator]. The objective of this study is to evaluate the major factors limiting S–ICD implantation in a real–world ACM patient population. Methods This multicenter retrospective observational study enrolled consecutive patients undergoing ICD implantation in primary or secondary prevention for ACM at the participating centers. The population was subdivided according to the execution of the preimplant S–ICD screening test and its result. Baseline clinical and instrumental data were analyzed to identify predictors of passing the screening test. Results 21 ACM patients (67% men) who underwent 24 S–ICD or TV–ICD implant procedures were enrolled. 70.8% of patients (N=17) were screened for S–ICD. Screening was not performed in 4 patients (17%): in one case due to an indication for resynchronization therapy and in three patients because they were implanted in the pre–S–ICD era. Screening failed in 53% of cases. The cause of the failures were the low voltages of the QRS (100% of the failures) and a poor stability of the trace in the different positions tested for significant variation of the QRS/T ratio (37.5% of the failures). No significant difference was noted between the clinical and instrumental characteristics of the two subgroups (Table 1), although the patients who passed the screening showed a trend towards a greater QRS amplitude in DI (0.52±0.29 vs 0.28±0.17 mV – P= 0.07) and to present a positive QRS in DI (100% vs 50%; P=0.08 – Table 2). Conclusions The use of the S–ICD in patients with ACM could be limited by some intrinsic characteristics of the disease. In a real–world cohort of patients affected by ACM, the presence of low QRS voltages on the surface ECG and positional morphology variations allowed S–ICD use in half of the patient candidates.

Funding Acknowledgements Type of funding sources: None. Introduction Previous studies have reported a significant decrease in ventricular sensing amplitude during follow-up in patients with arrhythmogenic cardiomyopathy (ACM) implanted with trans-venous implantable cardioverter defibrillator (ICD). No data are yet available on sensing amplitudes values over time for subcutaneous ICD (S-ICD). Low QRS voltage on surface ECG is one of the diagnostic clues in ACM. This, together with the progressive nature of the disease and the not-negligible incidence of inappropriate shocks due to oversensing, raise safety concerns on the use of S-ICD in this population. Aim The aim of this study was to evaluate the trend of QRS amplitude on subcutaneous ECG (S-ECG) over time in patients with ACM implanted with S-ICD. Methods We conducted a retrospective analysis on a cohort of consecutive patients with ACM implanted with S-ICD in two tertiary centers, prospectively enrolled in the home-monitoring program. The S-ECGs recorded by the S-ICD at the time of first and last data transmission were analyzed. The voltage amplitude was estimated for each QRS complex available, and the values obtained were compared between the two time points (i.e. baseline and last follow-up available). The primary endpoint of our study was the proportion of patients in which the decrease of QRS amplitude during follow-up was statistically significant. Results Eleven patients (1 female, 9%) were enrolled in this study. The mean age was 43±10 years. An exclusive right ventricular involvement was reported in 5 patients (46%), 2 patients (18%) had an exclusive left ventricular, and 4 (36%) a biventricular involvement. Three patients (27%) were implanted in secondary prevention. During a median follow-up of 9 months (IQR 6-17), 6 patients (55%, 95%CI 24-84%) experienced a statistically significant reduction in the S-ECG QRS amplitude (Figure A). Considering these 6 patients, the mean absolute reduction was -0.46±0.32 mV corresponding to a relative reduction of -19%±11%. Moreover, we found a statistically significant correlation between follow-up duration and QRS amplitude relative reduction (r=-0.89, p=0.018, Figure B). No patients experienced inappropriate shocks. Conclusions In a cohort of ACM patients implanted with S-ICD the majority of patients experienced a significant reduction in the amplitude of QRS voltage during follow-up, confirming a potential safety concern on the use of S-ICD in this population. Further studies are needed to investigate this issue.

Funding Acknowledgements Type of funding sources: None. Background Ventricular tachycardia (VT) ablation targeting conducting channels (CC)s based on timing of late potentials (LPs) during sinus rhythm (dechanneling) may facilitate a scar homogenization strategy without the need for extensive ablation and possibly lead to higher successful rate. Purpose We evaluated the feasibility and safety of a CC identification and ablation approach by means of an ultra-high density mapping system with a novel automated algorithm in ischemic VT procedures. Methods Consecutive patients indicated for ischemic VT ablation were prospectively included. A complete map of the left ventricle was performed prior and after ablation through the Rhythmia mapping system. Channels were defined as any signal activity bounded by anatomic and functional barriers and characterized through the Lumipoint (LM) tool and continuous activation was used on the whole ventricular substrate. Procedural end point was the elimination of all identified CCs by ablation at the CC entrance and exit followed by abolition of any residual LPs inside the CC. The ablation endpoint was noninducibility. Data are reported as mean±SD. Results A total of 36 channels were identified through LM from 28 patients (1.2±0.5 per patient): 21 (75%) patients had 1 CC, 6 (21.4%) had 2 CCs and 1 (3.6%) had 3 CCs. LPs were identified inside CCs in 19 cases (67.9%). In 8 cases (28.6%) LPs were present both inside and outside and in 1 (3.6%) case LPs were present only outside the CC. LPs inside channels covered an area of 7.6±5 mm2 with a ratio between LPs area and CCs’ area of 67.4±31.8%. In 12 (43%) cases LPs area covered more than 90% of the CCs’ area. At voltage map analysis a total of 34 CC were identified: 1 CC was present in 75% of the cases, 2 CCs in 17.9% and 3 CCs in 3.6%. LPs were identified only inside CCs in 46.4% of the cases, both inside and outside in 42.9% and only outside in 10.7%. Healthy tissue (voltage level≥0.5mV) was prevalent (68.2±17%), followed by intermediate voltage areas (0.5-0.05 mV; 31.1±17%) and very low voltage areas ( Conclusions In this experience, a channel identification approach through the advanced Lumipoint tool was more accurate than traditional voltage mapping and seems to be safe, feasible, and effective at least in the acute setting of ischemic VT ablation.

Introduction Previous studies have reported a significant decrease in ventricular sensing amplitude during follow–up in patients with arrhythmogenic cardiomyopathy (ACM) implanted with trans–venous implantable cardioverter defibrillator (ICD). No data are yet available on sensing amplitude values over time for subcutaneous ICD (S–ICD). Low QRS voltage on surface ECG is one of the diagnostic clues in ACM. This, together with the progressive nature of the disease and the not–negligible incidence of inappropriate shocks due to oversensing, raise safety concerns on the use of S–ICD in this population. The aim of this study was to evaluate the trend of QRS amplitude on subcutaneous ECG (S–ECG) over time in patients with ACM implanted with S–ICD. Methods We conducted a retrospective analysis on a cohort of consecutive patients with ACM implanted with S–ICD in two Italian tertiary centers, prospectively enrolled in the home–monitoring program. The S–ECGs recorded at the time of first and last data transmission were analyzed. The voltage amplitude was estimated for each QRS complex available, and the values obtained were compared between the two time points (i.e. baseline and last follow–up available). The primary endpoint of our study was the proportion of patients in which the decrease of QRS amplitude during follow–up was statistically significant. Results Eleven patients (1 female, 9%) were enrolled in this study. The mean age was 43±10 years. An exclusive right ventricular involvement was reported in 5 patients (46%), 2 patients (18%) had an exclusive left ventricular, and 4 (36%) a biventricular involvement. Three patients (27%) were implanted in secondary prevention. During a median follow–up of 9 months (IQR 6–17), 6 patients (55%, 95%CI 24–84%) experienced a statistically significant reduction in the S–ECG QRS amplitude (Fig. A). Considering these 6 patients, the mean absolute reduction was –0.46±0.32 mV corresponding to a relative reduction of –19%±11%. Moreover, we found a statistically significant correlation between follow–up duration and QRS amplitude relative reduction (r=–0.89, p = 0.018, Fig. B). No patients experienced inappropriate shocks. Conclusions In a cohort of ACM patients implanted with S–ICD the majority of patients experienced a significant reduction in the amplitude of QRS voltage during follow–up, confirming a potential safety concern on the use of S–ICD in this population. Further studies are needed to investigate this issue.

Introduction Percutaneous left stellate ganglion block (PLSGB) has been reported as a safety and effective procedure for the management of refractory arrhythmic storm (AS). In this report we present a case of a man with refractory AS effectively treated with PLSGB, subsequently candidate for an invasive procedure potentially associated with adrenergic stimulation and propose the use of this technique as pre–treatment strategy in this clinical setting. Case presentation A 57–year–old man was admitted to our hospital for AS. Past medical history revealed that two years earlier he had been treated with primary percutaneous coronary intervention for ST–segment elevation myocardial infarction. Four months before admission he underwent coronary artery bypass graft surgery with concomitant mechanical mitral valve replacement, closure of an interventricular defect and, considering the severe left ventricular disfunction, he was implanted with an automatic defibrillator in primary prevention. At the time of admission, he was treated with lidocaine infusion with remission of arrhythmic events. Comprehensive diagnostic workup revealed no overt triggers for AS. Five days after admission, the patient experienced recurrence of ventricular arrhythmias (VA), refractory to amiodarone, lidocaine, and magnesium infusion, increased pacing rate, and sedation with dexmedetomidine. PLSGB was then attempted with the injection of lidocaine and ropivacaine using an anatomical approach with complete remission of arrhythmic events. After a week free from VAs, a new AS was observed and PLSGB was repeated using the same modality with complete arrhythmic resolution. Considering the advanced heart failure, the patient was candidate to heart transplantation (HT) and, before undergoing gastro– and colonoscopy required for inclusion in the HT program, with the aim to reduce the risk of VA recurrences triggered by potential adrenergic stimulation, we pre–treated the patient with PLSGB using only ropivacaine, with successful induction of temporary Horner syndrome (Fig. A). The endoscopy procedures were performed successfully with no VA events and the patient was then discharged waiting for HT. Conclusion We propose the use of PLSGB as a pre–treatment strategy for patients at high–risk of VAs who are candidates for invasive procedures potentially associated with adrenergic stimulation. This report could be hypotheses–generating for further studies on this topic.

Introduction Life–threatening ventricular arrhythmias secondary to chest trauma without structural cardiac damage (i.e. commotio cordis [CC]) are a rare but dramatic cause of sudden cardiac death. We present a case of fast ventricular tachycardia (VT) induced by blunt chest trauma in a healthy man during sports activity. Case Presentation A 22–year–old man, competitive soccer player, was admitted to our hospital for VT. A few hours before admission, after a heavy ball impact in the chest during a soccer match, he suddenly reported fast and regular palpitation with lightheadedness and dyspnea, without loss of consciousness. The emergency medical service was activated, and the evaluation revealed a hemodynamically tolerated monomorphic VT with a rate of almost 285 bpm (Fig.A). Amiodaron infusion was ineffective and sinus rhythm (SR) was restored by electrical cardioversion. At the time of admission, he was asymptomatic. Familiar history, past medical history and physical examination were unremarkable. ECG revealed regular SR, with minimal right bundle branch conduction delay (Fig.B). Blood samples showed normal blood cells count, electrolyte concentrations and liver, kidney, and thyroid function; seriate high sensitivity troponin I determinations were negative. Echocardiography and cardiac magnetic resonance showed normal findings. Computed tomography angiography excluded coronary anomalies. Exercise test revealed no signs of cardiac ischemia and no effort–induced arrhythmias. The fluoroscopy–free unipolar and bipolar voltage maps showed normal electrograms throughout the right ventricle (Fig.C). No sustained arrhythmias were induced by programmed ventricular stimulation. The patient was then discharged with the indication to cardiology follow–up and the advice to avoid contact sports activities. Discussion VT is a rare presentation of CC. It has been proposed that CC occurs when a chest strike timed at the upstroke of the T–wave causes both ventricular depolarization trigger and altered dispersion of repolarization, mainly via activation of KATP channels. In the absence of structural heart disease (SHD), the usual presenting rhythm is ventricular fibrillation and there are no accepted mechanisms to explain monomorphic VT in this context. Some authors reported monomorphic VT after chest trauma as the first manifestation of arrhythmogenic cardiomyopathy. Therefore, a careful follow–up will be needed to exclude future development of SHD in this patient.

Background: When an implantable-cardioverter defibrillator (ICD) lead becomes non-functional, a recommendation currently exists for either lead abandonment or removal. Lead abandonment and subcutaneous ICD (S-ICD) implantation may represent an additional option for patients who do not require pacing. The aim of this study was to investigate the outcomes of a strategy of lead abandonment and S-ICD implantation in the setting of lead malfunction.Methods: We analyzed all consecutive patients who underwent S-ICD implantation after abandonment of malfunctioning leads and compared their outcomes with those of patients who underwent extraction and subsequent reimplantation of a single-chamber transvenous ICD (T-ICD).Results: Forty-three patients underwent S-ICD implantation after abandonment of malfunctioning leads, while 62 patients underwent extraction and subsequent reimplantation of a new T-ICD. The two groups were comparable. In the extraction group, no major complications occurred during extraction, while the procedure failed and an S-ICD was implanted in 4 patients. During a median follow-up of 21 months, 3 major complications or deaths occurred in the S-ICD group and 11 in the T-ICD group (HR 1.07; 95% CI 0.29–3.94; P = 0.912). Minor complications were 4 in the S-ICD group and 5 in the T-ICD group (HR 2.13; 95% CI 0.49–9.24; P = 0.238).Conclusions: In the event of ICD lead malfunction, extraction avoids the potential long-term risks of abandoned leads. Nonetheless the strategy of lead abandonment and S-ICD implantation was feasible and safe, with no significant increase in adverse outcomes, and may represent an option in selected clinical settings. Further studies are needed to fully understand the potential risks of lead abandonment.Clinical Trial Registration: URL: ClinicalTrials.gov Identifier: NCT02275637

Funding Acknowledgements Type of funding sources: None. Background Limited data exist on factors associated with radiation exposure during ablation procedures when a high definition mapping technology is used. Purpose To report factors associated with radiation exposure and data on feasibility and safety of a minimal fluoroscopic approach using the Rhythmia mapping system in supraventricular tachycardia (SVT) ablation procedures. Methods Consecutive patients indicated for arrhythmia ablation were enrolled in the CHARISMA study at 12 centers. We included in this analysis consecutive right-side procedures performed through a minimal fluoroscopy approach with the Rhythmia mapping system were analyzed. A 3D geometry of chambers of interest was reconstructed on the basis of the electroanatomic information taken from the mapping system. Fluoroscopy was used only if deemed necessary. The effective dose (ED) was calculated using accepted formula. For our purpose high dose exposure was defined as an ED greater than the median value of ED of the population exposed to radiation. Results This analysis included 325 patients (mean age = 56 ± 17 years, 57% male) undergoing SVT procedures (152 AVNRT, 116 AFL, 41 AP and 16 AT). During the study, 27481 seconds of fluoroscopy was used (84.6 ± 224 seconds per procedure), resulting in a mean equivalent ED of 1.1 ± 3.7 mSv per patient. The mean reconstructed RA volume was 99 ± 54 ml in a mean mapping time of 12.2 ± 7 min. The mean number of radiofrequency ablations (RFC) to terminate each arrhythmia was 9.4 ± 9 (mean RFC delivery time equal to 6.7 ± 6 min). 192 procedures (59.1%) were completed without any use of fluoroscopy; during the remaining 133 procedures (39.9%), 206.6 ± 313.4 seconds of fluoroscopy was used (median ED = 1.2 mSv). In a minority of the cases (n = 25, 7.7%) the fluoroscopy time was higher than 5 minutes (median ED = 6.5 mSv), whereas radiologic exposure time greater than 1 minute occurred in ninety cases (27.7%, median ED = 2.1 mSv). On multivariate logistic analysis adjusted for baseline confounders the RFC application time (OR = 1.0014, 95%CI: 1.0007 to 1.0022; p = 0.0001) was independently associated to an ED greater than 1.2 mSv, whereas female gender had an inverse association (0.54, 0.29 to 0.98; p = 0.0435). Acute success was reached in 97.8% of the cases. During a mean of 290.7 ± 169.6 days follow-up, no major adverse events related to the procedure were reported. Overall, the recurrence rate of the primary arrhythmia during follow-up was 2.5%. Conclusions In our experience, arrhythmias ablation through minimal fluoroscopy approach with the use of a novel ablation technology is safe, feasible, and effective in common right atrial arrhythmias. High-dose exposure occurred in a very limited number of cases, without any reduction of the safety and acute and long-term effectiveness profile.

Funding Acknowledgements Type of funding sources: None. BACKGROUND The Wearable Cardioverter Defibrillators (WCD) has been used extensively in Italy since 2015, following long years of experience in other countries. This technology provides temporary protection from Sudden Cardiac Death (SCD) for patients with an evolving risk profile that may not yet be eligible for an Implantable Cardioverter Defibrillator (ICD). Collecting national data on use of the device can help build a picture that will enable an understanding on how to use the WCD appropriately in the future. PURPOSE Our purpose has been to investigate WCD usage on a nationwide level. This is in terms of target population, average wear time, patient compliance, diagnosed and treated arrhythmic events and patient outcome once they stopped wearing the device. METHODS WEAR-ITA is a nationwide, multi-centre retrospective observational project. Patient data was retrospectively collected from the Italian hospitals that agreed to take part in the data collection for all patients fitted with a WCD between April 2015 to May 2018. All data refers to the range from the first day of wear until the end of use. RESULTS We collected data for 411 patients from 15 (75%) Italian regions. WCD use among the different regions was heterogeneous with a median of 0.5 (0.2-1.2) WCD wore/105 inhabitants. The mean age of the population was 55(±14) and the majority of patients were male (79%). Main WCD indication was non-ischemic cardiomyopathy with reduced ejection fraction (51%), ischemic etiology with severe systolic dysfunction (31%), uncertain or unidentified diagnosis (10%) that then revealed to be predominantly channelopathies or myocarditis and after ICD extraction (8%). Patients wore the WCD for a median of 59 (33-90) days and the median daily weartime was 23 (22,7-23,8) hours. In 15 patients (4%), the WCD recorded non sustained ventricular tachycardia (VT), 10 patients (2%) had hemodynamically well-tolerated sustained VT not needing a shock. 8 patients (2%) received effective appropriate shocks. Time to episodes were respectively 61 (14-61) days for non-sustained VT and 28 (19-70) days for VT/VF. 2 patients (0.5%) received inappropriate shocks for sinus tachycardia and atrial fibrillation (AF) respectively. WCD recorded new onset of supra ventricular tachycardia episodes in 12 patients (3%) and of atrial fibrillation (AF) in 7 patients (2%). 7 patients (2%) died while wearing WCD; none of them from SCD. At the end of the WCD use, 195 patients (47%) did not receive an ICD while 209 patients (51%)were implanted. CONCLUSIONS WCD is an effective therapy for the treatment of SCD with a very low complication rates. The indication and penetration in Italy is quite heterogeneous. The patient’s compliance is high over time. The incidence of appropriate shock is not negligible; only half of patients, who wore WCD, received an ICD. There is however still a requirement to conduct further randomized trials to understand which patients could most benefit from the use of WCD. Abstract Figure. Wereable Cardioverter Defibrillator

Funding Acknowledgements Type of funding sources: None. Background Defibrillation efficacy testing (DT) is recommended at implantation of subcutaneous implantable cardioverter–defibrillators (S-ICD). However, prior works found that adherence to this recommendation is declining in clinical practice. Purpose To compare survival from all-cause death and first ineffective shock (primary endpoint) and the composite of all-cause death, ineffective shock, inappropriate shock and device-related complication (secondary endpoint) between patients who underwent DT and those with omitted DT. Methods We analyzed 1652 consecutive patients who underwent S-ICD implantation in 60 Italian centers from 2013 to 2019. Results DT was not performed in 325 (20%) patients (no-DT patients). As compared with the DT group, these patients were older (51 ± 16 vs. 48 ± 15 years; p Conclusions Our data confirmed that DT is frequently omitted in current clinical practice, especially in older patients with worse systolic function. A strategy that omits DT did not appear to compromise the effectiveness of the S-ICD and no additional risk seems associated with DT omission at a mid-term follow-up. These data suggest that routine DT at S-ICD implant might not be necessary. Randomized trials are needed to confirm this finding.

Built environment design can be considered as an influential factor in the quality of life of people with autism spectrum disorder (ASD). This scoping review provides an overview of the current available literature on the relationship between people with ASD and built environment in the specific field of the design of autism-friendly spaces. The literature review allowed the identification of three main factors to be considered when designing for people with ASD—the sensory quality, the intelligibility, and the predictability of the built environment—and, for each of them, a description of the spatial requirements that have been recognized as fundamental according to the specific spatial needs of people with ASD.

Background Electrophysiological studies and ablation procedures expose both physicians and patients to a large amount of radiation. Most of 3-D mapping systems provide improved tracking of catheters, possibly allowing relevant reductions in radiation exposure. No data exists on the ability of the Rhythmia mapping system to minimize fluoroscopy time and dose. Purpose To report preliminary data on feasibility and safety of a minimal fluoroscopic approach using the Rhythmia mapping system in supraventricular tachycardia (SVT) procedures. Methods Consecutive patients indicated for arrhythmia ablation were enrolled in the CHARISMA study at 12 centers. For our purpose consecutive right-side procedures performed through a minimal fluoroscopy approach with the Rhythmia mapping system were analyzed. A 3D geometry of chambers of interest was reconstructed on the basis of the electroanatomic information taken from the mapping system. Fluoroscopy was used only if deemed necessary. Results This analysis included 266 patients (mean age = 57±17 years, 57% male) undergoing SVT procedures (120 AVNRT, 91 AFL, 32 AP, 11 AT and 12 other right atrial procedures). In all cases, diagnostic EP and ablation catheters were positioned using a low fluoroscopic electroanatomic guided approach. The mean fluoroscopy time needed for each procedure was 55±128 s. The median reconstructed RA volume was 92 [63–131] ml in a median mapping time of 11 [7–17] min. The median number of radiofrequency ablations to terminate each arrhythmia was 6 [3–12] (total RF delivery time of 291 [180–505] s). Sixty-five percent of the procedures (n=174) were completed with less than 10 s of fluoroscopy. Low fluoroscopy approach with less than 10 s (minimal fluoroscopy approach) was most frequently obtained in case of AVNRT (91, 76%) compared to other arrhythmias' ablation (83, 57%, p=0.001) Achievement of a minimal fluoroscopic approach was not affected by operator's experience (65% vs 66%, p=1.00, respectively within physician with more or less of 10 years of active practice), whereas it was affected by presence of a fellow in training during the procedure (72% without fellow vs 26% with fellow, p Conclusions In our preliminary experience, arrhythmias' ablation through minimal fluoroscopy approach with the use of a novel ablation technology seems to be safe, feasible, and effective in common right atrial arrhythmias. Use of fluoroscopy can be dramatically reduced in most cases, without any reduction of the safety and acute effectiveness profile. Funding Acknowledgement Type of funding source: None

Background The opportunity for people functioning in an atypical way to autonomously and fully interact with the city is often compromised or denied, due to the gap between their specific spatial needs and the physical and functional organization of the urban environment. The need to reconsider the living environments taking into account the vast diversity of people gained an increasing importance in the overall debate and specifically in the field of urban planning and design. The research aims at investigating the relationship between the urban environment and people with Autism Spectrum Disorder (ASD). Methods A scoping review of current available original studies research exploring the relationship between autism and built environment was conducted. PubMed, Scopus, PsychInfo and Web Of Science where searched. Studies included provided spatial requirements for designing autism friendly environment. Results In total, 801 studies were identified and 22 were included. Current researches and applications investigating the role of spatial configuration as a means for improving the autonomy of people with ASD almost exclusively focus on closed and dedicated spaces (residences, schools, care facilities, healing gardens) mostly devoted to children. Starting from this and the data collected, a first set of enabling urban spatial requirements addressing the atypical urban functioning of people with ASD - the reduction of sensory overload and the use of visual supports - in order to promote their possibility to walk autonomously and safely across the everyday city is proposed. Conclusions Despite the wide variability of the spectrum which makes it very difficult to define effective design criteria for all people with ASD, it's possible to identify a set of recurrent spatial needs. Furthermore, designing cities for people with ASD can also contribute to healthier and more inclusive urban environments for other groups of vulnerable inhabitants.

Background Because of the progress in diagnostic and therapeutic cardiovascular disease, the skills to be acquired during fellowship training has increased significantly. In particular, the evolution in arrhythmology and electrophysiology was fast in the last years. This could have created a gap between the training program during the fellowship and the new technologies, growing demand for re-defined educational requirements to ensure uniformity of knowledge and competence of those practicing in electrophysiology. Purpose The AIAC (Italian Association of Arrhythmology and Cardiostimulation) Young Pacing committee conducted a survey to obtain information the satisfaction on the educational and training obtained during the residency course by residents and young cardiologists (arbitrarily defined as age ≤ 40 years). Methods The survey was conducted from January to May 2019. Residents and young cardiologists were contacted to complete the survey by e-mail. They were asked to answer a questionnaire containing information about scholarly activity included satisfaction of educational and clinical proficiency in arrhythmology and electrophysiology and educational in electrophysiology after the residency. Results We obtained 334 answers to the survey. One hundred forty-six individuals (43.7%) were residents and 188 (56.2%) were young cardiologist. In Electrophysiology Department, 3-6 months were dedicated to Clinical Arrhythmology for 135 partecipants (40.4%), 1-2 months to cardiac pacing for 132 partecipants (39.5%) and 1-2 months to EP Lab for 139 partecipants (41.6%). Three hundred twenty-nine people responded to questions about satisfaction in educational. In terms of educational in Clinical Arrhythmology, 100 responders (30.4%) were "very satisfied", 105 (31.9%) were "satisfied" and 124 (37.7%) were "dissatisfied". About Cardiac Pacing, 84 responders (25.5%) were "very satisfied", 93 (28.3%) were "satisfied" and 152 (46.2%) were "dissatisfied". Only 51 (15.5%) participants were "very satisfied" with their training in Electrophysiology, whereas 81 (24.6%) were "satisfied" and 197 (59.9%) were "dissatisfied". About self-assessed clinical proficiency in Arrhythmology at the end of fellowship, 30 responders (9%) defined themselves as completely confident in Clinical Arrhythmology, 126 (37.7%) in Ambulatory Electrophysiology (ECG Holter and device check), 28 (8.4%) in cardiac pacing, 10 (3%) in performing electrophysiological study and nobody in catheter ablation. One hundred twenty-one (36.8%) participants improved their competence in Cardiac Arrhythmia Management attending courses after fellowship. Conclusion The survey underlines the need to fill a gap in order to address the needs of young interventional cardiologists and it may serve as a starting point for developing tailored educational initiatives.

Funding Acknowledgements NO FUNDING OnBehalf Rhythm Detect Registry Background Currently, when an implantable-cardioverter defibrillator (ICD) lead becomes nonfunctional, a class IIa recommendation exists for either lead abandonment or for removal. The benefits of removal include creation of an access for insertion of a new lead. However, the subcutaneous ICD (S-ICD) does not require the insertion of any leads into the cardiovascular system, and may represent an additional option for patients not requiring pacing. Purpose To report outcomes associated with a strategy of lead abandonment and S-ICD implantation in the setting of lead malfunction. Methods We analyzed all consecutive patients who underwent S-ICD implantation after abandonment of malfunctioning leads and we compared outcomes with those of patients who underwent transvenous extraction and subsequent reimplantation of a single-chamber transvenous ICD (T- ICD). Results 43 patients were implanted with an S-ICD after abandonment of malfunctioning leads, while in 62 patients extraction and subsequent reimplantation of a T-ICD. The two groups were comparable (Age 55 ± 16 vs. 54 ± 33years, BMI 26 ± 3 vs. 24 ± 4kg/m2, LVEF 43 ± 15 vs. 48 ± 8%). S-ICD defibrillation test success rate at implantation was 96% at 65J. In the extraction group, no major complications were reported during extraction, while the procedure failed and an S-ICD was implanted in 4 patients. During a median follow-up of 21 months, the rate of major complications was not higher in the S-ICD group than in the T-ICD group (HR 1.07; 95%CI 0.29–3.94; P = 0 .912; Figure), as well as the rate of minor complications (HR 2.13; 95%CI 0.49–9.24; P = 0 .238). Conclusions In case of ICD lead malfunction, extraction prevents potential long-term risks of abandoned leads, e.g. increased complications for a possible future mandatory extraction indication such as infection, and allows magnetic resonance imaging. Nonetheless in this series, the strategy of lead abandonment and S-ICD implantation appeared to be feasible and safe with no significant increase in adverse outcomes for patients not requiring pacing and may represent an option in selected clinical settings (very high risk or failed extractions, older patients, etc.). Longer follow-up studies are needed to fully understand the potential risks of lead abandonment. Abstract Figure

Funding Acknowledgements NO FUNDING Background Electrophysiological studies and ablation procedures expose both physicians and patients to a significant amount of radiation. Nowadays, most of 3-D mapping systems allow for improved tracking of catheters with possible reduction in radiation exposure. No data exists on the ability to minimize fluoroscopy time and dose while using the Rhythmia mapping system. Purpose To report preliminary data on feasibility and safety of a low fluoroscopic approach using the Rhythmia mapping system in SVT procedures. Methods The CHARISMA study is a non-randomized, multicenter, prospective study in which consecutive patients indicated for arrhythmia were enrolled. For our purpose consecutive right-side procedures performed through a low fluoroscopy approach with the Rhythmia mapping system were analyzed. The mapping system was used to create the 3D geometry of chambers of interest and anatomic reference points and to visualize the catheters from the beginning to the end of the procedure. Fluoroscopy was used only if deemed necessary. Results 204 unselected consecutive cases of SVT from 11 centers were included in the study (mean age = 55 ± 18 years, 53% male, 85 AVNRT, 75 AFL, 28 AP, 9 AT and 7 other right atrial procedures). In all the cases, diagnostic EP and ablation catheters were positioned using only the low fluoroscopic guided mapping approach. During the study, a total of 7157 s of fluoroscopy was needed in 204 patients (51 ± 137 s per procedure). One hundred fourty-one procedures (69%) were completed with less than 10 seconds of fluoroscopy, whereas in 169 (83%) of the cases the fluoroscopy time was lower than 60 seconds. Low fluoroscopy approach with less than 10 seconds was less frequently obtained in case of AFL (46, 61.3%) compared to AVNRT ablation (65, 76.5%, p = 0.041) whereas no differences were found comparing with AP (21, 75%, p = 0.248). The median reconstructed RA volume was 94[65-133] ml in a median mapping time of 11 [6-16] min. The median number of radiofrequency ablations to terminate each arrhythmia was 5 [3-12] (total RF delivery time of 293 [180-505] sec). A 100% rate of acute success was observed in our case series. No complications occurred. Conclusions In our preliminary experience, arrhythmias ablation through low fluoroscopy approach and the use of a novel ablation technology seems to be safe, feasible, and effective in common right atrial arrhythmias. Use of fluoroscopy can be nearly avoided in most cases, without any reduction of the safety and effectiveness profile.

The paper focuses on the relationship between cities and people with Autism Spectrum Disorder (ASD). Specifically, this research aims to provide practical guidelines on how to design urban policies and urban design projects, such that they improve the capabilities of people with ASD to walk across the city and access relevant public urban spaces and facilities. Although this is a well-defined field of research, this paper should be seen as a contribution to the debate on the understanding of disability as a product of processes of human-environment interaction and as an attempt to address issues of mobility for people with disabilities by taking into account their personal characteristics and capabilities. Current methodological and operational efforts on the role of spatial configuration as a means for improving the autonomy of people with ASD focus almost exclusively on the design of closed, separated, private spaces, devoted only to people with ASD (mainly children). Starting from these considerations, the paper describes a research project aimed at defining an integrated set of urban mobility policies and extra-small urban design projects to provide people with ASD a real opportunity of using their city.

After the 70s energy crisis the revamping of plants designed before this date is very attractive for improving energy recovery and lowering operation costs. A typical case is the oil refinery plant where an intensive usage of energy takes place and is a promising case for the application of energy saving solutions. In this work we focused our attention to an industrial crude oil distillation unit, evaluating the possibility to modify the feed conditions by installing a preflash drum or a preflash plate column. Real data plant were collected to obtain a reliable simulation of the unit by means of the software package Aspen Plus 13.0. To characterize the crude oil fed the TBP curve was used. The results obtained were compared with the plant data in terms of flow rate and product quality utilizing the ASTM D-86 curves and a good agreement was obtained. According to the specialized literature the preflash drum/column was placed at the end of the pre-heat train, just before the column furnace. The furnace is the bottleneck of the plant and with both the preflash devices it is possible to lower its energy consumption. However the energy reduction is associated to the decrease of one kind of distillates (light or middle). The choice of the best preflash device was made according to the production asset of the plant.

For an N-component separation, distillation systems with less than N-1 columns have the potential to save both energy and capital costs compared to the conventional simple column configurations where N-1 columns are employed. Recently, for four-component separations, Kim and Wankat [J.K. Kim, P.C. Wankat, Quaternary distillation systems with less than N-1 columns, Ind. Eng. Chem. Res. 43 (2004) 3838–3846] analyzed a few distillation systems with less than N-1 columns and presented tentative heuristics for selecting the best configuration among those studied. In this paper, a method for the systematic synthesis of all the distillation systems with less than N-1 columns is presented. Starting from the simple column configurations for the separation of an N-component mixture, a four-step procedure is formulated which systematically generates all the possible distillation systems with less than N-1 columns. First, the subspace of the possible thermally coupled configurations corresponding to the simple column configurations is generated. Then, the subspace of the possible thermodynamically equivalent structures corresponding to the thermally coupled configurations is produced. Finally, the subspace of the distillation systems with less than N-1 columns corresponding to the thermodynamically equivalent structures is achieved. The method is simple, easy-to-use and can systematically synthesize all the possible distillation systems with less than N-1 columns. It is shown that a large number of such distillation systems with less than N-1 columns have been achieved for the first time. This constitutes a complete new subspace. A case study shows the advantages of such distillation systems with less than N-1 columns over the other schemes. The significance to formulate a complete subspace of such systems is that, on the one hand, it can be used to further develop more reliable heuristics by simulations. On the other hand, an optimization framework can be formulated to screen the possible optimal system for a specific application.

Process intensification is currently considered as the main trend to improve process performance, and one of the major approaches to this regard is to reduce the number of pieces of equipment in the plant. For distillation systems, thermal coupling technique provides such an approach to retrofit the traditional simple column configurations through the elimination of the condenser and/or the reboiler. In this work, starting from the existing plant with the simple columns, two types of retrofit alternatives are proposed. The first includes the possible alternatives by eliminating all the condensers and reboilers involving the submixtures. The second includes all the possible alternatives when only some of the condensers and/or reboilers are eliminated at one time. The latter solution represents less modification to the existing plant. In addition, in order to investigate the capital investment for the modified plant, all the obtained alternatives through the recombination of the column sections have been compared. All the configurations were compared with respect to energy saving and the possibilities to reuse the plant equipment. The optimal solution was found to be the alternative that has the minimum modification to the existing plant. At the same time, it achieves a 23% savings on energy consumption and allows a maximum reuse of the pieces of the existing equipment.

This paper presents a general mathematical optimization model and the related deterministic algorithm for synthesizing heat-exchanger networks (HEN). The methodologies commonly used to solve a HEN problem are based on heuristic methods. These algorithms reach a presumed best solution with respect to the investigated set of process streams, whereas our approach determines the optimal configuration. In this paper the proposed method is applied to the solution of a few simple HEN synthesis problems and the results are compared with those obtained utilizing heuristic or meta-heuristic methods. HEN's problem is represented by a general mathematical model that can be applied to small and medium sized problems and is solved by using a deterministic method with a reasonably brief computation time. Notably, this approach can represent a unique general model of a wide class of heat-exchanger networks, independently of their specific physical configuration.

This paper presents an industrial case-study: the synthesis of partially thermally coupled and heat-integrated distillation systems applied to the light ends separation section of a crude distillation plant. The distillation systems presented in this work employ the thermal coupling and the heat-integration principles to significantly reduce the heat requirements with respect to the traditional simple column train. The work started from the simulation of the existing plant, by which the parameters of the system were identified. Then the possible sequences of simple columns with sharp splits were identified for the considered application, and all the columns of the configurations were designed. The corresponding thermally coupled sequences were obtained by using a simple procedure derived from the literature and the heat-integrated partially coupled configuration (HIPC) was also considered. In order to verify the examined distillation systems, all the simple and complex configurations were simulated by rigorous numerical models. On the basis of the numerical simulations, the energy requirements for each configuration were evaluated. A rating of the different plants was then performed, based on the total annual cost, allowing to identify the best plant configuration. A thermally coupled configuration showed the best performances for the considered separation.

An experimental study is presented on heavy metal pollution of soils. In particular, Pb2+, Zn2+, Cd2+ are considered as most representing the pollution of a Sardinian (Italy) area, where important mining activities connected to the extraction of blende and galena have been carried out in the past. Results of batch experiments involving adsorption from mono-component metal solutions are examined showing that at the fixed working pH of 6.5, a fraction of metal was always retained by ion exchange; surface precipitation was assumed to be responsible for the remaining fraction of metal retained. Competitive adsorption is also investigated by performing multicomponent sorption isotherms. The aim of the work was to evaluate the exchangeable fraction of metal retained in the soil, when it is contaminated by multicomponent heavy metal solutions. A mathematical model is presented which, using only parameters from binary adsorption data, is able to predict the fraction of metal retained by ion exchange from multicom...

Bioethanol has been considered as a green fuel and a valid alternative to reduce the dependence on fossil distillates. The development of an optimal separation process is considered as a key element in the design of an efficient process able to be cost effective and competitive. Despite many separation techniques are today available, distillation is up to now the frontrunner technology in most of the plants. In particular extractive distillation is considered as an energy efficient method to produce pure ethanol overcoming the purity limitations imposed by the water-ethanol azeotrope. The subspace of simple distillation configurations was generated considering the possibility to employ partial or total condensers to transfer the non-product mixtures between the columns, moreover different numbers of columns are considered. Once the most promising sequences are obtained, the complex columns are investigated. The complex column subspace is generated introducing one or more thermal couplings and considering the possibility to intensify the process combining the column sections performing the same separation task. All the configurations considered, simulated by means of Aspen Plus V 7.3, are compared considering the total condenser and reboiler duty as energy index. The capital costs and the solvent consumption are also taken into account in the final selection. Among all the complex configurations considered the two-column sequence can reduce the capital cost above 10% compared to the best simple column sequence. The performances for different solvents are also taken into account in the process alternatives comparison.

Solubilities at 25 °C of four amino acids (l-cystine, l-tyrosine, l-leucine, and glycine) in aqueous solutions at various pHs and NaCl concentrations (0, 1, 3 mol dm-3) are reported. The pH was varied from 0 to 13 using HCl or NaOH. The NaCl concentration strongly affects the solubilities of l-cystine, l-tyrosine, and l-leucine. In particular, the addition of NaCl increases the l-cystine solubility but reduces the solubility of l-tyrosine and l-leucine. The NaCl concentration has only a slight effect on the solubility of glycine. Experimental solubilities are correlated with the use of a chemical equilibrium model, good agreement in the pH range 1−12 was found. The analysis confirms the dependence reported in the literature between the solubility of amino acids and the salt concentration. For the amino acids examined, the parameters to calculate their solubilities in solutions with NaCl are also given.

A systematic analysis has been developed to investigate the performance of reduced-order models for multistage separation units in transient simulations. In particular, we have analyzed the accuracy of these models in reproducing some characteristic features of the dynamic behavior of the original full-order model, i.e. the eigenvalue of smallest modulus λmin and the singular values obtained through open-loop singular value decomposition. It is found that as the relative volatility increases the maximum reduction factor allowed by a prescribed accuracy decreases. The present analysis shows that, with the above limitations on the value of the reduction factor, reduced-order models are able to capture the true dynamics of the corresponding full-order models. Furthermore, the results indicate that the accuracy requirements in transient simulations are more stringent than in steady-state simulations, i.e. transient models require lower reduction factors for a given accuracy.

The stagewise collocation method is applied to reduce the full-order models used for simulating multistage separation units. In particular we refer to steady-state, high-purity x D up to 0. 9999) and symmetric ( x B =1− x D ) binary distillation columns. The performance of these reduced-order models is represented in a master plot which provides, rather synthetically, the model error as a function of the reduction order.

The properties of a carbon felt electrode have been experimentally investigated with special attention to its possible application in the electrochemical recovery of heavy metals. The mass transfer process has been studied by means of the reduction of ferricyanide and cupric ions for a flow-by electrode operating under limiting current conditions. An empirical correlation between the Sherwood and Reynolds numbers has been used to compare the experimental data with those obtained by other authors for different porous electrodes.

This paper reports on the adsorption isotherms that were determined on zeolite Na-Y at 298, 313, and 333 K for propane and propylene and at 298 K for butane, trans-butene, 1-butene, and cis-butene. The pressure of the experiments ranged from 5 {times} 10{sup {minus}2} to 30 kPa. The weight of adsorbed hydrocarbons was determined by a gravimetric method with a vacuum microbalance. The Henry constants were evaluated from the equilibrium measurements in the low-concentration range, and their sequence propane {lt} butane {lt} trans-butene {lt} propylene {lt} 1-butene {lt} cis-butene, was discussed in terms of the different adsorbate-adsorbent interactions. Equilibrium data, over the whole pressure range, were correlated by using the simplified model by Ruthven, based on statistical thermodynamics, and the appropriate parameters are reported. For C4 hydrocarbons, the intracrystalline diffusion process was also investigated and the Darken equation was used to correlate the uptake curves at the higher pressures. The diffusion coefficients were found in the order butane {gt} trans-butene {gt} 1-butene {gt} cis-butene and were compared to the available values in literature.

Vertical distribution of dissolved organic carbon (DOC) in the Sardinian Sea

In a study of patients suffering from craniosynostosis various pre- and post-operative parameters were identified that may affect subsequent intellectual capacity. In particular, facial malformations appeared to be closely correlated with impaired intellectual development. Other parameters included measurement of cranial circumference and volume; their subaverage values correlated with slight mental insufficiency. However, in the pre-operative period they cannot be used as prognostic indices because these relations were statistically not significant. The remaining parameters (neurological and electroencephalographic findings, post-operative re-ossification of the skull, pre-operative digital impressions, CT findings) did not seem to be related to intellectual development.

The results of a series of pulse experiments carried out in a fixed bed column packed with a strongly acid ion-exchange resin and with reference to the separation of an aqueous sucrose-betaine mixture are presented. These data were used to evaluate equilibrium and diffusion parameters for both key components in the frame of linear chromatography theory. The estimated values were used to design a simulated moving bed plant aimed to separate betaine from sucrose in beet molasses.

Recent studies have given lower and lower values for the solubility of hydrogen isotopes in the eutectic 83Pb-17Li alloy, a candidate breeding material for the blanket of fusion machines. Therefore, thermodynamic stability for the gaseous phase under the high pressure reached at the bottom of the alloy containers can be achieved even for very low tritium concentrations in the liquid phase. A mathematical model to determine when tritium bubble nucleation occurs at an appreciable rate is presented. This model is used to predict tritium production behavior in the next European Torus (NET) tokamak.

The experimental determination of infinite dilution activity coefficients (γ∞) of liquid mixtures is carried out by gas chromatographic and ebulliometric techniques. Both methods show inaccuracies due to experimental difficulties. This paper provides a comparative analysis of the influence of errors in measurements on the evaluation of γ∞ using ΔT — x and ΔP — x experimental data. It is shown that the errors in the determination of γ∞ from ΔP — x data are generally lower than those from ΔT — x ones

The application of direct vapour recompression to an existing plant, fractionating ethylbenzene-xylenes mixtures, has been studied. The behaviour of the saturated liquid and vapour curves for ethylbenzene in the Temperature-Entropy diagram has been evaluated theoretically by means of well known equations of state. The most important operating parameters of the process (as functions of ΔT) in the reboiler-condenser have been obtained. The economic analysis performed indicates that for the case considered, the best value for ΔTis about 6°C, but only a small energy saving can be achieved.

The galvanostatic desorption of hydrogen held in Pd-Ag electrodes in aqueous solutions with and without thiourea was studied. The effect of adsorption of poison molecules on the Volmer reaction and on the transfer process of hydrogen from the bulk to the permeation surface is reported. The experimental results obtained indicate that the chemisorption of thiourea causes a sharp decrease in the kinetic parameters of both steps involved in the overall oxidation process.

The kinetics of hydrogen evolution at an AISI 316 cathode in 0.1 M NaOH have been studied by determining the steady-state polarization behaviour and the open-circuit potential decay following interruption of the polarizing current. Electrochemical data have been obtained both for the electrode in stagnant solution and for an impinging jet electrode. The results suggest that the electrode behaviour, at a high mass-transfer rate, is characterized by the kinetics of hydrogen desorption through the molecular recombination path. Moreover, it appears that, in addition to the adsorption on the surface, hydrogen penetration into the layers beneath the surface can also occur. A lowering of the charge needed to change the degree of coverage of adsorbed hydrogen from zero to one and inhibition of the molecular recombination step induced by sulphide chemisorption may explain the observed behaviour when Na 2 S is added to the electrolyte.

The SdUMuty of acetlc acid In acetone-ethanol mlxtwes has been measured for temperatures ranglng from “ng point to 245.2 K. The experimental results are compared wlth values calculated by means of the Wlkon, NRTL, and UNIOUAC eq&kms, u#Wng the parametem from vapor-tiquid bqulllkJa, and with values predicted by the UNIFAC method. llw mean devlalhs between the measured and the calculated sohbHlWs are always very low.

HbA1 was determined in 15 G-6-PD-deficient subjects during a hemolytic crisis with hemoglobinuria due to ingestion of fresh fava beans. The same G-6-PD-deficient subjects were studied again 4 months after the crisis, when they were asymptomatic. 15 normal healthy children served as controls. A statistically significant decrease in HbA1 was observed in the favic subjects during hemolytic crises compared with their values 4 months later and those of the control group.